Partial Discharge (PD) Online Monitoring Systems

• The GoWatron GWPD-S-HFCT High-Frequency Current Transformer Partial Discharge Sensor is designed for insulation condition monitoring of power cables and cable accessories. It uses a high-frequency current transformer (HFCT) to detect partial discharge pulses propagating through cable screen earthing circuits and convert them into voltage signals. An associated acquisition unit processes and transmits these signals, providing data to help identify potential insulation defects.
• The split-core design allows installation without disconnecting the monitored earthing conductor, facilitating monitoring upgrades to existing installations. Wired and wireless configurations are available. Combined with power-frequency synchronisation and a compatible monitoring system, the sensor supports analysis of pulse amplitude, repetition rate, phase distribution and trends to assist insulation condition assessment and maintenance planning. Applications include substations, power plants, renewable energy installations and industrial power distribution facilities.

• The GWPD-S-AE from GoWatron is an acoustic emission (AE) partial discharge sensor designed for insulation condition monitoring of electrical equipment. It captures ultrasonic acoustic emissions generated by partial discharge to support equipment condition assessment and condition-based maintenance.
• The sensor has an ultrasonic detection frequency range of 40 ± 1 kHz and a detection dynamic range of −10 to 60 dBμV. Wireless and RS-485 wired versions are available, with internal or wireless power-frequency synchronisation. The sensor features magnetic mounting, an IP66 protection rating and an operating temperature range of −40 to +85 °C. Monitoring arrangements should suit the equipment structure and acoustic propagation conditions.

The GWPD-S-TEV TEV partial discharge sensor from GoWatron is designed for metal-enclosed electrical equipment, including high-voltage switchgear and ring main units (RMUs). It is available in a LoRaWAN wireless version and an RS-485 wired version. The sensor has a TEV detection bandwidth of 3–100 MHz and a TEV detection dynamic range of 0–60 dBmV. It supports internal or wireless power-frequency synchronisation. The wireless version incorporates a lithium thionyl chloride battery with a nominal battery life of more than six years, while the wired version uses an external power supply. With an IP66 protection rating, the GWPD-S-TEV provides measurement data for online partial discharge monitoring, insulation condition assessment and condition-based maintenance.

The GWPD‑HMI‑14 partial discharge monitoring HMI unit is a centralized monitoring and management host integrated with a 14‑inch industrial HMI touch screen. Equipped with a built‑in touch display, it requires no external monitor or host computer, enabling on‑site parameter configuration, sensor management, real‑time data reading and partial discharge spectrum viewing. The host supports connection of up to 200 partial discharge sensors, employing dual downstream communication modes: LoRaWAN wireless and RS485 wired. It locally analyzes and displays characteristic spectra, PRPS phase‑resolved spectra and cumulative PRPD phase‑resolved spectra, with built‑in local historical event storage. Via RS485 and RJ45 uplink interfaces, it connects to SCADA and power comprehensive monitoring platforms, enabling long‑term online partial discharge monitoring and insulation defect early warning for high‑voltage equipment such as switchgears, GIS and transformers. Supporting a wide range of AC/DC power supply in compliance with power industry standards and adopting wall‑mounted installation, it is suitable for use in substations, switching stations and industrial power distribution rooms.

The GWPD‑S‑3IN1 is a 3‑in‑1 partial discharge sensor integrating TEV (Transient Earth Voltage), AE (Acoustic Emission) and UHF (Ultra‑High Frequency) measurement technologies. TEV technology captures transient earth voltage signals coupled to the cabinet surface caused by internal partial discharge activities; AE technology collects acoustic wave signals generated by equipment insulation defects; UHF technology receives high-frequency electromagnetic waves excited by partial discharge events. The three independent detection principles complement and cross-verify each other, effectively overcoming the shortcomings of single-mode detection, such as susceptibility to on-site electromagnetic interference and missing discharge signals.

The GWPD-S-UHF is an intelligent UHF partial-discharge (PD) sensor developed for online PD monitoring of high-voltage switchgear. Employing the ultra-high-frequency (UHF) detection principle, it features a magnetic-mount structure that supports live-line installation without power outage. Equipped with a built-in high-energy lithium-thionyl chloride (LiSOCl₂) battery, the sensor offers a long service life of 5 to 8 years. It transmits PRPS and PRPD partial-discharge patterns via long-range LoRa-WAN wireless communication. The sensor enables non-contact online monitoring of internal insulation defects in switchgear, detects early insulation deterioration risks, and prevents catastrophic failures of high-voltage equipment.